1. Field of the Invention
The present invention relates generally to improvements in mechanisms that serve to animate a doll's facial features, and, more particularly, pertains to a mechanism in which a single motor drives simulated jaw movement, eyeball movement and eyelid movement. The eyelid movement is achieved in a manner such that it can be initiated at any time independent of jaw or eyeball position.
2. Description of the Prior Art
Miniaturization of electronic circuitry has enabled the incorporation of a surprising amount of sophisticated capability within a doll's interior. The coordinated movement of legs, arms, hands, head and various facial features has become a rather commonplace ability of modern dolls. In addition, such movements can be coordinated with a sound track emanating from the doll. An increased number of movements that are coordinated with a sound track results in a more lifelike appearance.
Numerous mechanisms have been devised to animate various facial features of dolls or mannequins to impart a more lifelike appearance. Movement of eyes and eyelids are critical for such lifelike animation, and, if the doll is to speak, movement of the mouth or jaw is also most desirable. Mechanisms have been disclosed that serve these three functions as, for example, in U.S. Pat. No. 2,641,866. Typically, an electric motor, wound spring or other drive means, is employed to rotate a series of gears, pulleys, cams and cranks that actuate various followers, levers, rods and arms to achieve this animation.
A shortcoming of mechanisms that are driven by a single drive means is that the sequence of movements is typically very repetitive, therefore rather predictable, and as a result, has a rather artificial appearance. While the use of complex cam profiles somewhat lessens the movements' rather "mechanical" appearance, independence of one movement from another is not thereby achieved. For instance, it could be observed that for every so many eye movements or jaw movements, the eyelids are blinked. Incorporation of additional drive means provides more degrees of independence but complicates matters by increasing size, weight, cost and complexity. Similarly, addition of mechanisms that can selectively couple and decouple certain functions from a single drive means increases complexity and cost.